A couple of
anomalies to do with jumping and the time in the air that follows
it were already mentioned in the previous article. There are more that
probably should have been noted too. Although id fixed the Qtest bug
allowing +moveup and +movedown to operate
when jumping, there still remain a couple of ways you can manoeuvre in
mid-air that, strictly speaking, are a little strange.
One of these everyone has probably noticed - by pressing
+back you can cancel out your +forward jump
velocity, and vice versa. So if you are going to land a little bit too
far beyond a ledge and topple into some lava, you can always try
putting on the air-brakes. In fact, you can even start going
backwards again before you land.
The other is related, but harder to get right unless you know the
trick. You can steer in mid-air as well; and in fact you can manage to
jump and turn a hundred and eighty degrees to get round a
corner. Learning to do this to get to the Quad in dm3 is
a good idea (well, actually you can also do this one with a straight
jump if you get the angle and timing right.) You can see a good
example of a 180 degree grenade-jump in the Quake
done Quicker movie if you playdemo e4m4.
The key to doing this sort of mid-air steering is simple enough -
having started going +forward, don't do a
-forward command once you have jumped. In
other words, hang onto whatever control it is you use to move forward
all the time you are in the air; until you let go you will be able to
change direction just as if you were on the ground. (Thanks to Karel
Suhajda for pointing me in the right
direction 
concerning this one.)
This particular bug/feature was fixed for QuakeWorld; it only works in yer regular Quake. You can put on the air-brakes in QW, but you can't go backwards, and you can't steer in mid-air. Another bug bites the dust.